<!DOCTYPE html>
<html>
<head>
  <meta charset="UTF-8">
  <title>Hello World Extension</title>
  <link rel="stylesheet" href="styles.css">
</head>
<body>
  <div class="container">
    <h1>Hello World!</h1>
    <p>这是我的第一个Chrome插件</p>
    <button id="changeColor">将页面变成绿色</button>
  </div>
  <script src="popup.js"></script>
</body>
</html> 